Method for determining the current position of a rail vehicle, computer program and rail vehicle tracking system

Abstract

Method for determining the current position of a rail vehicle (1) on a rail line (3) travelled by the rail vehicle (1), having the following features: a) detecting the soil structure (5) below the rail line (3) travelled by the rail vehicle (1) below the ground surface by means of a penetrating ground radar (10), b) transmitting the ground data (12) characterising the ground structure (5) recorded by the ground radar (10) by means of remote data transmission from the rail vehicle (1) to a remote evaluation point (2), c) comparing the soil data (12) received at the evaluation station (2) with data records (22) of a soil database (21) in which soil data characterising the soil structure of all rail lines (3) travelled by the rail vehicle (1) are stored, d) determining the current position of the rail vehicle (1) based on the detection of a sufficient degree of correlation of the ground data (12) received by the rail vehicle (1) with at least one data set (22) of the ground database (21) and a position reference of this data set (22) stored in the ground database (21).

Description

The invention relates to a method for determining the current position of a rail vehicle on a rail track traveled by the rail vehicle according to claim 1.There are already various proposals for the locating of rail vehicles on rail sections, i.e. for the determination of the respective current position of such a rail vehicle. For example, point-shaped locating information can be transmitted to the rail vehicles by complicated installations in the track. For this purpose, RFID transponders are anchored in the track bed, for example, which are read out by special antennas of the rail vehicles when they pass over. These transponders are assigned to a specific position in databases.A further possibility for rail vehicle positioning is vehicle-side sensors, for example laser scanners, cameras, radar, GPS. DE 10 2013 104 088 A1 discloses a rail vehicle locating system in which the contours of characteristic elements above the track bed of the rail section being traveled are scanned by means of a surroundings sensor arranged on the rail vehicle. In particular, the contours of the rails or landmarks can be scanned.DE 10 2012 215 533 A1 discloses a position determination of a rail vehicle. From DE 10 2015 209 101 A1 a method for generating a map for an autonomous vehicle is known. WO 2008 / 017 821 A2 discloses a mobile threat detection. DE 101 04 946 B4 discloses a method and a device for determining the current position and for monitoring the planned path of an object. DE 10 2010 013 442 A1 discloses a method and a device for supplying information to the driver of a rail vehicle. DE 195 32 104 C1 discloses a method and a device for determining the position of at least one location of a lane-guided vehicle. DE 196 11 774 A1 discloses a method for locating a lane-guided vehicle in its own right and a device for carrying out the method.The invention is based on the object of further simplifying and improving the locating of rail vehicles.This object is achieved by a method for determining the current position of a rail vehicle on a rail track on which the rail vehicle is travelling according to claim 1. The method includes the following features: a) detecting the ground structure beneath the road surface on which the rail vehicle is travelling by means of a penetrating ground radar, b) transmitting the ground data which are detected by the ground radar and characterize the ground structure by means of remote data transmission from the rail vehicle to a remote evaluation point, c) comparing the ground data received in the evaluation point with data sets of a ground database in which ground data characterizing the ground structure of these rail distances are stored for all rail distances on which the rail vehicle is travelling, d) determining the current position of the rail vehicle on the basis of the detection of a sufficient degree of correlation of the ground data received from the rail vehicle with at least one data set of the ground database and a position reference of this data set stored in the ground database.Such a determination of the current position of a rail vehicle can be realized cost-effectively and with little installation effort. In particular, no infrastructure-side extensions are required on the rail paths, such as the transponders mentioned at the beginning. It is only necessary to equip the rail vehicles with a penetrating ground radar. Furthermore, the rail vehicle requires the possibility of remote data transmission to a remote evaluation point, which is necessary in rail vehicles, however, in any case also for other data transmissions.According to the invention, the use of a penetrating ground radar is proposed, which is also referred to as geo radar or, in the English language, as ground penetrating radar or radio echo sounding. The adjective "penetrating" is understood here in the sense of "penetrating into the ground". In contrast to the prior art, the ground surface is thus not detected by such a ground radar. Such a penetrating ground radar allows the detection of ground structures below the ground surface, i.e. in the ground, e.g. at a depth of 20 cm to 50 cm. Characteristic ground data can be acquired by means of the ground radar, which, similar to a fingerprint, unambiguously characterize a specific geoposition on the rail track. In contrast to the detection of external surface features, i.e. features not in the interior of the ground, the ground data detected by the penetrating ground radar have a character that is invariable over a long term, i.e. they are practically not subject to any temporal changes, one can see targeted damage or natural catastrophes. The ground data recorded by the penetrating ground radar are moreover independent of environmental influences and seasonal influences, e.g. ice and snow deposits.The use of a penetrating ground radar in combination with a vehicle operated on a rail track brings about additional synergy effects, which result from the fact that in the case of rail vehicles the lateral guidance of the vehicle by the rails is predefined on the infrastructure side. Accordingly, only a relatively small area of the ground is to be detected and stored in the ground database. During the detection, i.e. during the detection of the ground structure by the rail vehicle, the sampling frequency can be selected to be relatively moderate, i.e. low, which is also made possible by the lateral guidance by the rails. In this way, the data rates required for the transmission of the ground data by remote data transmission can be kept within reasonable limits.A further advantage of the invention is that the possibly computationally expensive comparison of the ground data detected by the ground radar with the data of the ground database does not have to take place in the rail vehicle itself, but at the remote evaluation point. In this way, the technical equipment required in the rail vehicle can be monitored and kept cost-effective.Thus, no special computing capacity is required in the rail vehicle. The storage outlay for the ground database can also be kept within limits because it is not necessary to store the complete geographical area of the rail network, but only data along the rail sections.The ground data transmitted from the rail vehicle by means of the remote data transmission can be, for example, the raw data of the ground radar, or data already pre-processed in one way or another, wherein preferably only a low-computational pre-processing takes place in the rail vehicle in order to limit the effort involved there. For example, signal processing can take place in the rail vehicle, and optionally, in order to limit the data rate for the remote data transmission, data compression of the transmitted data can take place.The ground radar can capture the ground data one-dimensionally, e.g. linearly, or two-dimensionally. The ground radar allows the ground to be detected by high-frequency electromagnetic waves. Different technologies can be used for this purpose, e.g. the pulse radar or the continuous wave radar, either continuously or discretely frequency-modulated.The ground database stores ground data characterizing the ground structure of these rail routes for all rail routes that can be traveled by the rail vehicle. The totality of the rail paths is also referred to as a rail network or a track network. The ground database can be filled with corresponding ground data data sets, for example, by a specific measuring rail vehicle gradually traveling along the rail paths and acquiring corresponding ground data with a penetrating ground radar. The acquisition of the ground data for filling the ground database can also be carried out by the normal rail vehicles which have the ground radar, for example by first operating them in a learning mode in which the acquired ground data are not yet used for the position determination, but for filling the ground database.Data records are stored in the ground database, which record, on the one hand, the desired ground structure expected for a specific geoposition in the rail network. In addition, each data record has a reference to this geoposition to which the acquired ground data belong. A position reference of the data set is thereby formed. If the comparison of the ground data of the rail vehicle received in the evaluation point with the data of the ground database is carried out in a manner according to the invention, it must be assumed already on the basis of detection inaccuracies that frequently there is no exact agreement of these ground data. Therefore, statistical methods determine a degree of correlation between the ground data recorded in the rail vehicle and the ground data data records of the ground database. If a certain sufficient degree of correlation is reached, a match of the ground data is assumed and the position reference stored for the corresponding data record of the ground database is adopted as the current position of the rail vehicle.The current position of the rail vehicle determined according to the invention can then be output, e.g. visually on an image display device, or used for further processing in the system.The process of comparing and evaluating the ground data including the determination of the current position of the rail vehicle according to steps c) and d) can be carried out, for example, by a map matching method. Thus, the map matching method can be carried out in the evaluation point in such a way that in this method the ground data received from the rail vehicle is correlated ("matched") with the data records of the ground database and the position of the rail vehicle is determined on the basis of the correlated received ground data and data records of the ground database.The invention also allows the position of the rail vehicle to be determined in a uniformly selective manner, i.e. it is possible to distinguish on which of a plurality of parallel tracks the rail vehicle is located. This is necessary, for example, in the vicinity of station stations or in the case of multi-track tracks.The determination of the current position of the rail vehicle can be additionally improved by detecting further signals and / or by plausibility checks. For example, the rail vehicle may additionally have a receiver of a global navigation system, e.g. GPS or Galileo, and in this way determine an independent position signal at least under sufficient reception conditions, which position signal may be used for matching with the position information obtained from the ground data. A further possibility for supporting the position information obtained from the ground data is a comparison with characteristic route points of the rail network, for example with switches (sensor fusion). This also allows the required computing effort for the position determination to be significantly reduced. The region to be examined for map matching can be kept as small as possible.According to an advantageous development of the invention, it is provided that a network plan is updated and / or created in the evaluation point by the instantaneous positions of a plurality of or all rail vehicles located thereon being reproduced on an image display device in a representation of the rail network. This has the advantage that the positions of the various rail vehicles are always kept at the current state and can be clearly shown.According to an advantageous development of the invention, it is provided that the current position of a rail vehicle determined in the evaluation point is transmitted back to the rail vehicle by remote data transmission. This has the advantage that the personnel located in the rail vehicle can also be informed about the exact position of the rail vehicle at any time. The current position of the rail vehicle may be visually displayed on an image display device of the rail vehicle, for example.According to an advantageous further development of the invention, it is provided that the current position of the rail vehicle is determined on the basis of a sequence of several ground data consecutively detected by the ground radar and their comparison with a sequence of data sets of the ground database. By using a sequence of several ground data acquired in chronological succession by the ground radar instead of a single data record of such ground data, a ground data profile acquired via a section of the rail section can be determined and used for the evaluation and compared with a corresponding sequence of data records of the ground database, which represents a corresponding stored ground data profile. In this way, the accuracy of the position determination of the rail vehicle can be improved. It is also possible by this further development of the invention to reduce the amount of data required for the ground data, for example by keeping the resolution of individual ground data sets low or by further reducing the sampling frequency.According to an advantageous development of the invention, it is provided that the evaluation point is designed as a single central evaluation point. In this way, the effort for determining the position of the rail vehicle is additionally reduced, since the memory requirement is low and only at one location, namely the central evaluation location, the ground database and corresponding computers have to be available for evaluation.The object mentioned at the outset is furthermore achieved by a computer program having program code means, configured to carry out a method of the type explained above when the method is executed on a computer. The advantages explained above can also be realized in this way. The method can be carried out in particular in split fashion, wherein the rail vehicle-side steps a) and b) are carried out in the rail vehicle, i.e. by a computer of the rail vehicle, and the evaluation point-side steps c) and d) are carried out in the evaluation point, i.e. by a computer of the evaluation point.The object mentioned at the beginning is furthermore achieved by a rail vehicle locating system according to claim 7.The advantages explained above can also be realized in this way. A data center can also be used as a computer in the aforementioned sense.The invention is explained below with reference to an exemplary embodiment using the drawing FIG. 1. FIG. 1 shows a rail vehicle locating system in schematic representation.FIG. 1 shows a rail vehicle 1, which can be designed, for example, as a traction vehicle or as another rail vehicle, for example as a wagon. The rail vehicle 1 travels on a rail track 3. Below the track bed 4 there is a further underlying surface 6. In the terminology of the present invention, the floor structure is understood to mean in particular the structure of the underlying surface 6, optionally also of the track bed 4.The rail vehicle 1 has a penetrating ground radar 10. The ground radar 10 transmits electromagnetic waves toward the ground, i.e., the track bed 4 and the ground 6, and receives reflected signals of the transmitted waves. By way of example, it is assumed that a ground structure 5 is detected at the current position of the rail vehicle 1. The ground radar 10 generates ground data 12 from the received reflected signals of the transmitted waves, which data characterize the ground structure 5. The ground data 12 are transmitted in the rail vehicle 1 from the ground radar 10 to a data remote transmission device 11 of the rail vehicle 1. The data transmission device 11 is configured in particular for wireless data transmission, e.g. by means of radio transmission. The data remote transmission device 11 transmits the ground data 12 to a remote evaluation point 2.The evaluation station 2 has its own data transmission device 20 which receives the ground data 12. The data transmission device 20 makes the received ground data 12 available to a computer 23 of the evaluation station 2. The computer 23 has software (computer program) with which a comparison of the ground data 12 with data records 22 stored in a ground database 21 is carried out. The data records 22 stored in the ground database 21 can represent, for example, a digital map of the rail network.If an adequate correlation with the ground data 12 is recognized for a specific data record 22 of the ground database 21, the current position (geoposition) of the rail vehicle 1 on the rail track 3 is determined on the basis of a position reference assigned to this data record 22. This current position of the rail vehicle 1 can be visually displayed, for example, in the evaluation location 2. By way of example, FIG. 1 shows an image display device 24 in this regard, on which a network plan 25 of the rail network is shown. The rail track 3 is represented in the network plan 25 by a line 26. The current position of the rail vehicle 1 on the rail track 3 is reproduced to the network plan 25 by a position marker 27 on the line 26.The evaluation point 2 can also transmit the current position of the rail vehicle 1 via the data remote transmission device 20 to the data remote transmission device 11 of the rail vehicle 1 and thus provide the current position in the rail vehicle 1.

Claims

Method for determining the current position of a rail vehicle (1) on a rail track (3) traveled by the rail vehicle (1), having the following features: a) detecting the ground structure (5) below the rail track (3) traveled by the rail vehicle (1) below the ground surface by means of a penetrating ground radar (10), b) transmitting the ground data (12) detected by the ground radar (10) and characterizing the ground structure (5) by means of remote data transmission from the rail vehicle (1) to a remote evaluation point (2), c) comparing the ground data (12) received in the evaluation point (2) with data sets (22) of a ground database (21) in which ground data characterizing the ground structure of these rail tracks are stored for all rail tracks (3) traveled by the rail vehicle (1), d) determining the current position of the rail vehicle (1) on the basis of the detection of a sufficient degree of correlation of the ground data (12) received from the rail vehicle (1) with at least one data record (22) of the ground database (21) and a position reference of this data record (22) stored in the ground database (21).Method according to the preceding claim, characterized in that a network plan (25) is updated and / or created in the evaluation point (2) by the instantaneous positions of a plurality of or all rail vehicles located thereon being reproduced on an image display device (24) in a representation of the rail network and / or being used for other further use, in particular traffic management.Method according to one of the preceding claims, characterized in that the current position of the rail vehicle (1) determined in the evaluation point (2) is transmitted back to the rail vehicle (1) by remote data transmission.Method according to one of the preceding claims, characterized in that the current position of the rail vehicle (1) is determined on the basis of a sequence of a plurality of ground data (12) acquired one after the other by the ground radar (10) and the comparison thereof with a sequence of data sets (22) of the ground database (21).Method according to one of the preceding claims, characterized in that the evaluation point (2) is designed as a single central evaluation point.Computer program having program code means, set up to carry out a method according to one of the preceding claims when the method is executed on a computer (23).Rail vehicle locating system having the following features: a) one or more rail vehicles (1) having the following features: a1) a penetrating ground radar (10) arranged on the rail vehicle (1) for detecting the ground structure (5) below the ground surface below the rail track (3) traveled by the rail vehicle (1), a2) a data remote transmission device (11) arranged on the rail vehicle (1), which is set up for transmitting the ground data (12) detected by the ground radar (10) and characterizing the ground structure (5) to a remote evaluation point (2), b) the evaluation point (2) having a data remote transmission device (20) set up for data communication with the data remote transmission device (11) of the rail vehicle (1), c) the evaluation point (2) having a ground database (21), in which ground data characterizing the ground structure of these rail paths are stored for all rail paths (3) drivable by the rail vehicle (1), d) the evaluation point (2) has a computer (23) which is configured to compare the ground data (12) received in the evaluation point (2) with data sets (22) of the ground database (21) and to determine the current position of the rail vehicle (1) on the basis of the detection of a sufficient degree of correlation of the ground data (12) received by the rail vehicle (1) with at least one data set (22) of the ground database (21) and a position reference of this data set (22) stored in the ground database (21).

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